Method of manufacturing electrical contacts on organic semiconductors

Abstract

A method for producing electrical contacts on organic semiconductors is described. The method, which involves low energy impact and can be carried out under ambient conditions, comprises covering the relevant surface of the semiconductor with a layer of an appropriate solvent: a metal leaf having an appropriate thickness and work function containing metal oxide impurities is deposited onto the area treated in this manner. Electrical contacts with elevated conductivity are obtained by evaporating the solvent. One embodiment of the invention describes a family of crystalline semiconductors, preferably based on perylene or α-quaterthiophene, provided with the electrical contacts according to the method described herein and provided with particular structural characteristics. The use of metal leaf satisfying the above-stated requirements (for example imitation gold leaf, gold leaf etc.). in the above-described method is furthermore described.

1 . A process for producing electrical contacts on the surface of an organic semiconductor, comprising the steps of:
 (a) depositing a layer of solvent onto the surface of the semiconductor:   (b) depositing onto the surface treated in said manner a metal leaf which is partially oxidised at least on its lower surface;   (c) evaporating the solvent.   
     
     
         2 . Process according to  claim 1 , wherein the metal leaf is a gold, copper, silver or aluminium leaf. 
     
     
         3 . Process according to  claim 1 , wherein the metal leaf has a work function comprised between 3 and 6 eV. 
     
     
         4 . Process according to  claim 1 , wherein the metal leaf has a thickness of less than 500 nanometres. 
     
     
         5 . Process according to  claim 1 , wherein the metal leaf is a material which is already known in the restoration, fine arts or craft trades sector. 
     
     
         6 . Process according to  claim 5 , wherein the metal leaf is selected from among imitation gold leaf gold leaf aluminium leaf and similar materials. 
     
     
         7 . Process according to  claim 1 , wherein the solvent is water. 
     
     
         8 . Process according to  claim 1 , carried out at ambient temperature, pressure and humidity. 
     
     
         9 . Process according to  claim 1 , wherein the semiconductor used has a consistent crystal structure and retains it throughout the whole process. 
     
     
         10 . Process according to  claim 1 , wherein the semiconductor is selected from among rubrene, α-quaterthiophene, perylene or mixtures thereof. 
     
     
         11 . Process according to  claim 1 , wherein the semiconductor is incorporated into an electronic or optoelectronic device. 
     
     
         12 . Use of partially oxidised metal leaves in accordance with  claim 1  in producing electrical contacts on the surface of an organic semiconductor. 
     
     
         13 . An organic semiconductor provided with electrical contacts. produced in accordance with the process according to  claim 1 . 
     
     
         14 . Semiconductor according to  claim 13  having a consistent crystal structure. 
     
     
         15 . Semiconductor according to  claim 14 , wherein the crystal structure is monoclinic. 
     
     
         16 . Semiconductor according to  claim 15 , composed of perylene and/or α-quaterthiophene. 
     
     
         17 . An electronic or optoelectronic device comprising an organic semiconductor provided with electrical contacts, said contacts being produced by means of the process according to  claim 1 . 
     
     
         18 . Device according to  claim 17 , wherein the semiconductor has a consistent crystal structure. 
     
     
         19 . Device according to  claim 18 , wherein the crystal structure is monoclinic. 
     
     
         20 . Device according to  claim 19 , wherein the semiconductor is composed of perylene and/or α-quaterthiophene. 
     
     
         21 . A process for manufacturing electronic or optoelectronic devices comprising the step of including, in said device, an organic semiconductor provided with electrical contacts produced in accordance with  claim 1 .